Large dynamic range cameras

ABSTRACT

A digital camera includes a plurality of channels and a processing component operatively coupled to the plurality of channels. Each channel of the plurality of channels includes an optics component and a sensor that includes an array of photo-detectors. The processing component is configured to separately control an integration time of each channel, where a first integration time of a first channel is less than a second integration time of a second channel. The processing component is also configured to combine data from the plurality of channels to generate an image.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.11/788,122, filed Apr. 19, 2007, which is a Continuation-In-Part of U.S.patent application Ser. No. 11/212,803, filed Aug. 25, 2005, whichclaims priority to U.S. Provisional Patent Application No. 60/695,946filed on Jul. 1, 2005 and to U.S. Provisional Patent Application No.60/604,854 filed on Aug. 25, 2004; U.S. patent application Ser. No.11/788,122 also claims priority to U.S. Provisional Patent App. No.60/795,882 filed Apr. 28, 2006. Each of the above-referenced patentapplications is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The following disclosure relates generally to optical devices and moreparticularly to expanding the dynamic exposure range in digital cameras.

BACKGROUND

Image sensors can be realized with semiconductors based on theircapability to convert locally impinging light energy into a proportionalamount of electronic charge. This electronic charge “Q” is oftenreferred to as photo-charge, and can be integrated within the pixel on astorage device such as a reverse biased diode or as a pre-chargedmetal-oxide-semiconductor capacitance. The finite charge storagecapacitance within each pixel limits the amount of integratedphoto-charge. Dynamic range is measured as the ratio of the maximumphoto-charge that can be meaningfully integrated in a pixel of theimager to the pixel noise level.

Intrascene dynamic range refers to the range of incident light that canbe accommodated by an image sensor in a single frame of pixel data.Examples of high dynamic scenes range scenes include an indoor room witha window view of the outdoors, an outdoor scene with mixed shadows andbright sunshine, and evening or night scenes combining artificiallighting and shadows. In a typical charge coupled device (CCD) or CMOSactive pixel sensor (APS), the available dynamic range is in a range of1,000:1 to about 4,000:1. Unfortunately, many outdoor and indoor sceneswith highly varying illumination have a dynamic range significantlygreater than 4,000:1. Image sensors with intrascene dynamic rangesignificantly greater than 4,000:1 are required to meet many imagingrequirements.

The dynamic range of an image sensor can be increased by using multipleexposure times and/or integration times. For example, U.S. Pat. No.4,647,975 describes a method based on the acquisition of two or moreimages, each having an exposure time. Once numerous images have beentaken at different exposure times, the images have to be fused or mergedto form one single piece of pixel information having a wide dynamicrange. U.S. Pat. Nos. 4,647,975, 5,168,532, and 5,671,013 disclose theuse of a selection rule to combine information from the most suitable ofthe multiple images. The merged pixel information or value is thenmultiplied by a suitable factor that corrects for the respectiveexposure times. This method however exhibits undesirable temporalaliasing if the scene or camera is moving because the two or more imageshaving different exposure times are captured using the same image sensorand thus are not captured concurrently.

Despite improvements in solid-state image sensor and digital cameratechnology, the light signal or brightness range of scenes often exceedsthe dynamic range of the sensor. For this reason, numerous methods havebeen described in the art of image sensors to extend the dynamic orsignal range. A summary of some methods is presented in: “Wide dynamicrange sensors”, Optical Engineering, Vol. 38, No. 10, pp. 1650-1660,October 1999. Methods to provide wide dynamic range imaging capabilitywith a single image sensor include: (a) logarithmic or compressedresponse photo-detection; (b) multiple integration and charge storagecapability within each pixel; (c) frequency based sensors, where thesensor output is converted to pulse frequency; (d) local integrationtime control, where different areas within the sensor can have differentexposure times; (e) signal charge versus integration time rate (signalslope) measurement; (f) analog to digital conversion per pixel; and (g)autonomous pixel control. These methods require complex pixel circuitryand are difficult to implement in small pixel areas without taking uparea required for the photo-detection mechanism (such as a photodiode).

Typical scenes imaged by digital cameras have light levels that span arange including low light (1-100 lux), moderate light (100-1000 lux),and bright light (1000-1,000,000 lux) under outdoor conditions. Toaccommodate lighting changes from scene to scene (the interscene dynamicrange) an electronic shutter is used to change the integration time ofall pixels in an array from frame to frame. To cover a single scene thatmight involve indoor lighting (100 lux) and outdoor lighting (100,000lux), the required intrascene dynamic range is approximately 10,000:1,corresponding to 80 dB (14-bits). This exceeds the dynamic range of asingle image sensor using a single integration time (typically 3,100:1corresponding to 70 dB (12-bits)). Therefore, there is a need for adigital camera in which the effective single-frame dynamic exposurerange is expanded.

INCORPORATION BY REFERENCE

Each patent, patent application, and/or publication mentioned in thisspecification is herein incorporated by reference in its entirety to thesame extent as if each individual patent, patent application, and/orpublication was specifically and individually indicated to beincorporated by reference diagram of a digital camera that includesmultiple channels, under an embodiment.

FIG. 1 is a block diagram of a conventional digital camera.

FIG. 2 is a block diagram of a digital camera that includes multiplechannels, under an embodiment.

FIG. 3 is a block diagram of a digital camera subsystem, under anembodiment.

FIG. 4 is a digital camera subsystem, under an alternative embodiment.

FIG. 5 is a digital camera subsystem, under another alternativeembodiment.

FIG. 6 is a digital camera subsystem, under still another alternativeembodiment.

FIG. 7 is a block diagram of a method for forming images having a largedynamic range, under an embodiment.

FIG. 8 is a block diagram of a digital camera, under an embodiment.

FIG. 9 is an exploded view of a digital camera subsystem, under anembodiment.

FIG. 10 is a block diagram of a digital camera having a three array/lensconfiguration, under an embodiment.

FIG. 11 is a block diagram of a digital camera subsystem that employsseparate arrays on one image sensor, under an embodiment.

FIG. 12 is a block diagram of arrays, each of which receives arespective color as passed by a respective lens, under an embodiment.

FIG. 13 is a block diagram of processing circuitry of a digital camerasubsystem, under an embodiment.

FIG. 14 is a block diagram of signal processing circuitry, under anembodiment.

FIG. 15 is an exploded perspective view of a digital camera, under anembodiment.

FIGS. 16A-16D are schematic exploded representations of one embodimentof an optics portion, under an embodiment.

FIGS. 17A-17C are schematic representations of a sensor array, under anembodiment.

FIG. 18 is a schematic cross-sectional view of a digital cameraapparatus, under an embodiment.

FIG. 19 is a schematic perspective view of a digital camera apparatushaving one or more optics portions with the capability to provide colorseparation, under an embodiment.

FIG. 20A is a block diagram of a processor of a digital camerasubsystem, under an embodiment.

FIG. 20B is a block diagram of a channel processor of a digital camerasubsystem, under an embodiment.

FIG. 20C is a block diagram of an image pipeline of a digital camerasubsystem, under an embodiment.

FIG. 20D is a block diagram of an image post processor of a digitalcamera subsystem, under an embodiment.

FIG. 21 is a block diagram of digital camera system, including systemcontrol components, under an embodiment.

DETAILED DESCRIPTION

Digital camera systems and methods are described below that provide anexpanded effective single-frame dynamic exposure range. The digitalcamera systems and methods, collectively referred to herein as digitalcamera systems, generally include two or more camera channels. Eachchannel includes an optics component and an image sensor having anactive area including multiple picture elements (pixels). Each sensor iscontrolled under or with an independent signal integration time asdescribed in detail below. Image capture by the camera is performedusing the multiple camera channels, and each camera channel iscontrolled during a frame under an independent integration time. Theintegration time for each channel can be automatically controlled and/orcontrolled in response to a user input. A wide range of integrationtimes are available for use in an embodiment. The images obtained ineach channel under the different integration times are obtainedsimultaneously or nearly simultaneously, so undesirable temporalaliasing from moving scenes or camera motion is minimized.

The digital camera systems, through the use of multiple integrationtimes, enable formation of an image having a wide dynamic range bycombining the data from all camera channels to form a composite singleframe. The wide dynamic range of an embodiment is generally greater thatthe dynamic range obtained by a conventional digital camera with asingle image sensor channel and one integration time.

Conventional digital cameras may have a maximum photo-signal storagecapacity that limits the dynamic range of the particular system. Thephoto-signal charge is stored on a capacitor within the pixel area. Thecharge handling capacity is limited by the maximum voltage swing in theintegrated circuitry and the storage capacitance within the pixel. Theamount of integrated photo-charge is directly related to the time theimage sensor collects and integrates signal from the scene. This isknown as integration time. A long integration time is desired for weaksignals since more photo-charge is integrated within the pixel and thesignal-to-noise of the digital camera is improved. Once a maximum chargecapacity is reached, the sensor no longer senses image brightnessresulting in data loss. Therefore, the use of a single integration timefor the entire field of view creates an imaging dilemma in conventionalcameras. The digital camera integration time can be set to image lowlight levels and saturate bright signals or image high light levels andnot detect low light levels (since the integrated photo-charge from lowlight levels is below the signal-to-noise of the sensor).

The digital cameras described herein overcome this dynamic rangelimitation through the use of multiple camera channels, includingmultiple optics and image sensors on a single integrated circuit (IC) orsemiconductor substrate. The multiple camera channels are configured toimage the same field of view simultaneously, and each operatesindependently under a different integration time. The digital camera caninclude, for example, a 3 by 3 assembly of image sensors, perhaps threesensor of each color (e.g., red (R), green (G), and blue (B)) and theintegration time of the sensors associated with each color can bevaried, for example, each color can have three distinct values (e.g.,0.1 msec, 1 msec, and 10 msec integration time, respectively). The datafrom all sensors can be digitally combined to provide a much greaterdynamic range within one frame of digital camera data. The raw digitalcamera data could be used by digital signal processing of the scene. Thedigital data can also be stored and displayed to exhibit low light orbright light characteristics as desired.

Exposure is the total amount of light allowed to fall on a sensor duringthe process of taking a photograph. Exposure control is control of thetotal amount of light incident on a sensor during the process of takinga photograph.

In contrast to exposure control, which is used by conventional digitalcameras to manage dynamic range, the digital camera systems of anembodiment use integration time control to control the time theelectrical signal is integrated on a charge storage device (capacitance)within a sensor (pixel), as described herein. Integration time control,also referred to as “focal plane shutter” control, controls the time theelectrical signal is integrated or accumulated by controlling a switch(e.g., charge integration switch) coupled or connected to the sensor ora photo-detection mechanism of a sensor. For example, the chargeintegration switch is placed in a state to allow charge to accumulatewithin the sensor for a period of time approximately equal to theintegration time corresponding to that sensor; upon completion of theintegration period, the switch is placed in a state to transfer theaccumulated charge as a photo-signal to a processing component. Digitalcamera components or circuitry are configured to allow independentcontrol of the charge integration switch associated with each sensor,thereby making possible dynamic range control for each sensor. Theintegration time control can be executed (depending on readoutconfiguration) according to a number of techniques, for example, rollingmode and/or snap-shot mode to name a few.

Generally, the digital camera systems of an embodiment provide digitalcameras with large effective single-frame dynamic exposure ranges. Thedigital camera systems include multiple channels. Each channel includesan optics component and sensor comprising an array of photo-detectors.The sensors of the camera channels are integrated on a semiconductorsubstrate. The camera systems include a processing component coupled tothe channels. The processing component is configured to separately andsimultaneously control an integration time of each channel. Theintegration time of at least one channel is controlled relative to theintegration time of at least one other channel so that an image formedby combining data of a frame received simultaneously from the channelshas a relatively large dynamic range.

A digital camera according to an embodiment includes multiple (e.g., twoor more) closely spaced image sensor camera channels integrated on or ina common semiconductor substrate. Each sensor camera channel has its ownoptics, photo-detection and readout mechanism that includes a pluralityof picture elements (pixels) with independent signal integration timecontrol. The pixel area, including photo-detector and circuitry, can beas small as 2 μm by 2 μm but is not so limited. The individual camerachannels of an embodiment look at the same field of view.

Each image sensor camera channel for example includes a plurality ofpixels, wherein at least two channels may be individually interrogated,for example, the channels can independently be reset, integrate chargefor a predetermined and unique time period, and read out. The digitalcamera further comprises circuitry and/or algorithms for individuallyinterrogating the camera image sensor camera channels, for combiningoutput values of said subsets into combined output values to from a highdynamic range composite image within a single frame of data, and forelectrically outputting said composite image.

The digital camera systems and methods of an embodiment use a range ofintegration times, T_(long) to T_(short), for each channel to increasesignificantly the dynamic range of the digital camera, while insuring asignal overlap between the images. For example, the dynamic range of adigital camera using the methods described herein can be increased fromapproximately 70 dB to 90 dB using a ratio of T_(long)/T_(short) equalto 25. The use of a long integration time in one camera channel allowsdark objects to be detected, whereas very bright objects are not, due tosaturation of the corresponding pixels storage capacity. In contrast,the use of a short integration time in another channel enables detectionof bright objects, whereas very dark objects are not detected due to aweak signal below the noise floor of the pixel. The digital camerasystems and methods described below suitably combine the output signalsof both exposures to increase the dynamic range of the digital camera.

The sensor camera channel output values P_(short) to P_(long), measuredwith different exposure times, of the camera system described below maynot be related ideally through the ratio (t=T_(long)/T_(short)) forexample, P_(long) may be close to but not identical with t-P_(short) dueto non-linear photo-response. For this reason the methods of anembodiment include algorithms that combine the two values to form alarge dynamic range composite image in a manner that does not lead toimage artifacts and pattern noise.

FIG. 1 is a block diagram of a conventional digital camera 100. Thedigital camera 100 includes a lens assembly 110, a color filter arraylayer 112, an image sensor 116, and an electronic image storage media120. The camera 100 also includes a power supply 124, a peripheral userinterface (represented as a shutter button) 132, a circuit board 136(which supports and electrically interconnects the aforementionedcomponents), a housing 140 (including housing portions 141, 142, 143,144, 145 and 146) and a shutter assembly (not shown), which controls anaperture 150 and passage of light into the digital camera 100. Amechanical frame 164 is used to hold the various parts of the lensassembly 110 together. The lens assembly 110 includes lenses 161 and 162and one or more electromechanical devices 163 to move the lenses 161 and162 along a center axis 165. The lenses 161 and 162 can be made up ofmultiple elements arranged together to in any combination to form anintegral optical component. Additional lenses can be used if necessary.The electromechanical device 163 portion of the lens assembly 110 andthe mechanical frame 164 portion of the lens assembly 110 can includenumerous components and/or complex assemblies.

The color filter array layer 112 has an array of color filters arrangedin a Bayer pattern (e.g., a 2 by 2 matrix of colors with alternating redand green in one row and alternating green and blue in the other row,although other colors may be used). The Bayer pattern is repeatedthroughout the color filter array. In some imaging applications, such asbroadband visible imaging color filter layers 112 are not required. Inother color imaging applications different color filters are used orcolor separation capability is built into the image sensor detectionmechanism.

The image sensor 116 contains a plurality of identical photo detectors(alternatively referred to as “picture elements” or “pixels”) arrangedin a matrix. The number of photo detectors is usually in a range ofhundreds of thousands to millions. The lens assembly 110 spans thediagonal of the array.

Each of the color filters in the color filter array 112 is disposedabove a respective one of the photo detectors in the image sensor 116,such that each photo detector in the image sensor receives a specificband of visible light (e.g., red, green or blue) and provides a signalindicative of the color intensity of the respective band. Signalprocessing circuitry (not shown) receives signals from the photodetectors, processes the signals, and ultimately outputs a color image.

The peripheral user interface 132, which includes the shutter button,can further include one or more additional input devices (e.g., forsettings, controls and/or input of other information), one or moreoutput devices, (e.g., a display for output of images or otherinformation) and associated electronics.

FIG. 2 is a block diagram of a digital camera 200 that includes multiplechannels, under an embodiment. The digital camera 200 includes a digitalcamera subsystem 210 and an electronic image storage media 220. Thedigital camera 200 also includes a power supply 224, a peripheral userinterface (represented as a shutter button) 232, a circuit board 236(which electrically interconnects and/or supports one or morecomponents), a housing 240 (including housing portions 241, 242, 243,244, 245 and 246) and a shutter assembly (not shown), which controls anaperture 250 and passage of light into the digital camera 200.

The digital camera subsystem 210, also referred to herein as the “DCS”210, includes one or more camera channels (e.g., four camera channels260A-260D) and replaces (and/or fulfills one, some or all of the rolesfulfilled by) the lens assembly 110, the color filter 112 and the imagesensor 116 of the digital camera 100 described above. The four camerachannels 260A-260D have a configurable or selectable signal integrationtime control that can be made optimal for a range of incident opticalsignal levels. The combination of signals from the four camera channelsrepresenting the varying integration times allow a greater range ofincident photo-signal levels to be detected. Each camera channel,working in conjunction with a selected or programmed integration time,can be optimized to collect an incident light range; for example theoptical f-number, photo-detector design, in-pixel circuitry and readoutcircuitry can be selected for low, medium or high light levels.

The peripheral user interface 232, which includes the shutter button,may further include one or more additional input devices (e.g., forsettings, controls and/or input of other information), one or moreoutput devices, (e.g., a display for output of images or otherinformation) and associated electronics.

The electronic image storage media 220, power supply 224, peripheraluser interface 232, circuit board 236, housing 240, shutter assembly(not shown), and aperture 250, may be, for example, similar to theelectronic image storage media 120, power supply 124, peripheral userinterface 132, circuit board 136, housing 140, shutter assembly (notshown), and aperture 150 of the digital camera 100 described above.

FIG. 3 is a block diagram of a digital camera subsystem 210, under anembodiment. As described above, the subsystem 210 includes one or morecamera channels. The digital camera subsystem 210 for example is a fourchannel signal integration time control system (e.g., four camerachannels 260A-260D), but the embodiment is not limited to four channelsand can include any number of camera channels. Each of the camerachannels 260A-260D includes an optics component or portion and a sensorcomponent or portion. The optics component can have different opticalf-number among the included camera channels but is not so limited. Forexample, camera channel 260A includes an optics portion 290A and asensor portion 292A. Camera channel B includes an optics portion 290Band a sensor portion 292B. Camera channel C includes an optics portion290C and a sensor portion 292C. Camera channel D includes an opticsportion 290D and a sensor portion 292D. The optics portions of the oneor more camera channels are collectively referred to herein as an opticssubsystem. The sensor portions of the one or more camera channels arecollectively referred to herein as a sensor subsystem. Each camerachannel has a selectable integration, and the integration time settingbetween channels is selected to cover a range of incident light levelonto the digital camera.

In the digital camera subsystem 210, each channel can have the sameconfiguration or a different configuration relative to at least oneother channel of the subsystem 210. For example, in some embodiments,the camera channels are all identical to one another. In some otherembodiments, one or more of the camera channels are different, in one ormore respects, from one or more of the other camera channels. In some ofthe latter embodiments, each camera channel may be used to detect adifferent color (or band of colors) and/or band of light than thatdetected by the other camera channels. For example, in some embodiments,one of the camera channels (e.g., camera channel 260A) detects redlight, one of the camera channels (e.g., camera channel 260B) detectsgreen light, and one of the camera channels (e.g., camera channel 260C)detects blue light; any other color combinations can also be used. Thecolor detection capability can be provided by optical materials, colorfilter layers over the detector, and/or color separation mechanismsbuilt into the photo-detector structure.

Thus, the optics portions can each be the same or different relative toother optics portions. In some embodiments, all optics portions areidentical. In some other embodiments, one or more of the optics portionsare different, in one or more respects, from one or more of the otheroptics portions. For example, in some embodiments, one or more of thecharacteristics (for example, but not limited to, its type ofelement(s), size, and/or performance) of one or more of the opticsportions is tailored to the respective sensor portion and/or to helpachieve a desired result. For example, if a particular camera channel isdedicated to a particular color (or band of colors) or wavelength (orband of wavelengths) then the optics portion for that camera channel maybe adapted to transmit only that particular color (or band of colors) orwavelength (or band of wavelengths) to the sensor portion of theparticular camera channel and/or to filter out one or more other colorsor wavelengths.

Similar to the optics portion, if the digital camera subsystem 210includes more than one sensor portion, configurations of the sensorportions can be the same or different relative to one or more othersensor portions. In some embodiments, the sensor portions are similar oridentical to the other sensor portions. In some other embodiments, oneor more of the sensor portions are different, in one or more respects,from one or more of the other sensor portions. In some embodiments, forexample, one or more of the characteristics (for example, but notlimited to, its type of element(s), size, and/or performance) of one ormore of the sensor portions is tailored to the respective optics portionand/or to help achieve a desired result. For example, if a particularcamera channel is dedicated to a particular color (or band of colors) orwavelength (or band of wavelengths) then the sensor portion for thatcamera channel may be adapted to have a sensitivity that is higher tothat particular color (or band of colors) or wavelength (or band ofwavelengths) than other colors or wavelengths and/or to sense only thatparticular color (or band of colors) or wavelength (or band ofwavelengths). The sensor portion for that camera may be adapted foroptimized operation by features such as array size, pixel size, pixeldesign, image sensor design, image sensor integrated circuit process andelectrical circuit operation.

The digital camera subsystem 210 further includes a processor. Theprocessor includes an image processor portion 270 (referred to as imageprocessor 270) and an integration time controller portion 300 (referredto as controller 300). The controller is a component of the variableintegration time that provides integration time control for each of thecamera channels. The processor 270 is coupled or connected to the one ormore sensor portions (e.g., sensor portions 292A-292D) via one or morecommunication couplings or links, represented by a signal line 330. Acommunication link may be any kind of communication link including butnot limited to, for example, wired (e.g., conductors, fiber opticcables) links, wireless links (e.g., acoustic links, electromagneticlinks, and/or any combination of links including but not limited tomicrowave links, satellite links, infrared links), and/or combinationsof wired and/or wireless links.

The operation of the digital camera subsystem 210 is described below.For example, the user selects a desired incident light range and thecamera automatically adjusts the integration time setting between thecamera channels to give an optimal dynamic range result. Alternativelythe user can select an integration time for each camera channel. Anoptics portion of a camera channel receives light from within a field ofview and transmits one or more portions of such light. The sensorportion receives one or more portions of the light transmitted by theoptics portion and, in response, generates an output signalrepresentative or indicative of information of the received light. Theoutput signal from the sensor portion is coupled to the image processor270 which, as is further described below, can generate an image based atleast in part on the output signal from the sensor.

When the digital camera subsystem 210 includes more than one camerachannel, the image processor 270 generates a combined image based atleast in part on the images from two or more of the camera channels. Forexample, in an embodiment, each of the camera channels is dedicated to adifferent color (or band of colors) or wavelength (or band ofwavelengths) relative to the other camera channels, and the imageprocessor 270 combines the images from the two or more camera channelsto provide a full-color large dynamic range image. In other embodiments,all camera channels provide the same color capability (such as RGB Bayerpatterns on each color channel) and the image processor 270 combines thecamera channels to create a large dynamic range image.

The image processor 270 can also combine sensor channels and analyze theresultant image on a frame by frame basis. The image processor 270 cansend a signal to the integration time controller 300 for real-time, ornear real-time, dynamic range management by adjustment of each channel'sintegration time control. This same method can be used to optimize asubsequent single field exposure for optimal picture taking.

In the digital camera subsystem 210 of an embodiment, the four camerachannels 260A-260D are configured to detect RGB light. Each of thecamera channels can be identical in configuration or optimized for aspecified light level as described above; for example if camera channel260A is intended to detect dim light the optics f-number in that channelcould be reduced. The pixel photo-detector can be configured for lowdark current and the pixel circuitry configured for low noise. Theintegration time control on camera channel 260A is increased to allowincreased signal collection. Some pixels in channel 260A would saturatedue to incident light levels; this would be determined electrically anddata from those pixels would not be used in creating a composite image.Channels 260B-260D would be configured and operated in a similar fashionto sense larger incident light levels.

In the digital camera subsystem 210 of another alternative embodiment,the four camera channels 260A-260D are configured to provide differentimaging capability; for example channel 260A is configured to detect redand blue light, while channel 260B is configured to detect green light.The combined response from channels 260A and 260B of this embodimentthus comprises a RGB color camera. The integration time settings forchannels 260A and 260B are configured or set for low incident lightlevels. Camera channel 260C is configured to collect red and blue lightand channel 260D is configured to collect green light. The combinedimages of channels 260C and 260D generate a second RGB imagingcapability and the integration time of channels 260C and 260D isconfigured for high incident light levels.

In the digital camera subsystem 210 of yet another alternativeembodiment, camera channel 260A is configured for red light, camerachannel 260B is configured for green light, and camera channel 260C isconfigured for blue light. Camera channels of a single color can providesuperior low light response since the color transmission with eachchannel is high (high transmission color filters within the opticalpath) and the photo-detection mechanism in each camera channel isconfigured or set for a specific color for high responsivity. Thecombined response from channels 260A, 260B and 260C thus comprises a RGBcolor camera. The integration time settings for channels 260A, 260B and260C are configured for low incident light levels. Camera channel 260Dis configured for RGB light detection and the integration time of thatchannel configured or set for high incident light levels. Various othercombinations of integration times among the channels are possible underthe description herein.

FIG. 4 is a digital camera subsystem 410, under an alternativeembodiment. The digital camera subsystem 410 for example is a threechannel signal integration time control system (e.g., three camerachannels 260A-260C), but the embodiment is not limited to three channelsand can include any number of camera channels. The digital camerasubsystem 410 includes camera channel 260A configured for RGB light,camera channel 260B configured for RGB light, and camera channel 260Cconfigured for RGB light. The integration time of camera channel 260A isconfigured for low light, the integration time of camera channel 260B isconfigured for medium high, and the integration time of camera channel260C is configured for high incident light levels. The combined responsefrom camera channels 260A, 260B and 260C provides a large dynamic rangeimaging capability.

The digital camera subsystem 410 of one alternative configuration is athree channel system in which camera channel 260A is configured for RGBlight, camera channel 260B is configured for RGB light, and camerachannel 260C is configured for RGB light. The integration time of camerachannel 260A is configured for medium light, the integration time ofcamera channel 260B is configured for medium high, and the integrationtime of camera channel 260C is configured for high incident lightlevels. The combined response from camera channels 260A, 260B and 260Cprovides a large dynamic range imaging capability. Various othercombinations of integration times among the channels are possible underthe description herein.

While the triangular layout configuration of the three camera channels260A-260C can provide area reduction advantages in imager layout andprocessing on semiconductor wafers, and can provide optical symmetrybetween the channels, alternative layout configurations are possibleusing the three camera channels. For example, one alternative layoutincludes a 1 by 3 vertical configuration. Another alternative layoutincludes a 1 by 3 horizontal configuration.

FIG. 5 is a digital camera subsystem 510, under another alternativeembodiment. The digital camera subsystem 510 for example is a twochannel signal integration time control system (e.g., two camerachannels 260A-260B), but the embodiment is not limited to two channelsand can include any number of camera channels. The digital camerasubsystem 510 includes camera channel 260A configured for RGB light andcamera channel 260B configured for RGB light. The integration time ofcamera channel 260A is configured or set for low light and camerachannel 260B is configured for high incident light levels. The combinedresponse from camera channels 260A and 260B provides a large dynamicrange imaging capability. Alternative configurations of the two camerachannels include a 1 by 2 vertical layout and a 1 by 2 diagonal layoutof camera channels.

The digital camera subsystem 510 of one alternative configuration is atwo channel system in which camera channel 260A is configured for RGBlight and camera channel 260B is configured for RGB light. Theintegration time of camera channel 260A is configured or set for lowlight and camera channel 260B is configured for medium incident lightlevels. The combined response from camera channels 260A and 260Bprovides a large dynamic range imaging capability.

The digital camera subsystem 510 of another alternative configuration isa two channel system in which camera channel 260A is configured for RGBlight and camera channel 260B is configured for RGB light. Theintegration time of camera channel 260A is configured or set for mediumlight and camera channel 260B is configured for high incident lightlevels. The combined response from camera channels 260A and 260Bprovides a large dynamic range imaging capability. Various othercombinations of integration times among the channels are possible underthe description herein.

FIG. 6 is a digital camera subsystem 610, under still anotheralternative embodiment. The digital camera subsystem 610 is a sixchannel signal integration time control system (e.g., six camerachannels 260A-260F), but the embodiment is not limited to six channelsand can include any number of camera channels. The digital camerasubsystem 610 includes camera channel 260A configured for incident redlight, camera channel 260B configured for green light, and camerachannel 260C configured for blue light. The combined response fromcamera channels 260A, 260B and 260C provides a first RGB color camera.The integration time settings for camera channels 260A, 260B and 260Care configured for low incident light levels.

The digital camera subsystem 610 also includes camera channel 260Dconfigured for incident red light, camera channel 260E configured forgreen light, and camera channel 260F configured for blue light. Thecombined response from camera channels 260D, 260E and 260F provides asecond RGB color camera. The integration time settings for camerachannels 260D, 260E and 260F are configured for high incident lightlevels.

The digital camera system described above includes a method for formingimages having a large dynamic range. FIG. 7 is a block diagram forforming images 700 having a large dynamic range, under an embodiment.The method for forming images 700 can be implemented using the imageprocessor 270 and/or the 300 integration time controller as describedabove with reference to FIGS. 3-6. The method of an embodiment includesselecting 702 an integration time for each image sensor camera channelfrom a range of integration times. The photo-signal from each camerachannel is integrated 704 within a single frame of data, and theresultant photo-charge for each pixel is stored within that pixel. Thephoto-signal is read from each pixel and each pixel response iscorrected 706 for one or more of non-linearity, gain and offset asappropriate and/or required. The method combines 708 data of themultiple camera channels, and thus provides a continuous monotonicrepresentation of the combined pixel response from low to high incidentlight levels. The method of an embodiment includes processing (e.g.post-processing), storing, displaying and/or outputting the resultantlarge dynamic range image from the combined camera channels. Informationof the resultant image and/or any post-processing operations is used todetermine integration time control settings 710 that provide optimumdynamic range on subsequent frames of data but is not so limited.

FIGS. 8-21 illustrate further examples of apparatus and systems in whichthe imaging module and focusing method embodiments disclosed above canbe implemented. FIG. 8 is a block diagram of a digital camera 800, underan embodiment. The digital camera includes a digital camera subsystem802, a circuit board 812, a peripheral user interface electronics 810(here represented as a shutter button, but could also include displayand/or one or more other output devices, setting controls and/or one ormore additional input devices etc), a power supply 806, and electronicimage storage media 804. The digital camera 800 may further include ahousing and a shutter assembly (not shown), which controls an aperture814 and passage of light into the digital camera 800.

FIG. 9 is an exploded view of the digital camera subsystem 802, under anembodiment. In this embodiment, the digital camera subsystem includes animage sensor 904, an optics frame (also referred to as a frame) 902, andlenses 912A-912D. The frame 902 is used to mount the lenses 912A-912D tothe image sensor 904. The image sensor, or imager die 904 generallyincludes a semiconductor integrated circuit or “chip” having severalhigher order features including multiple arrays 904A-904D and signalprocessing circuits 908 and 910. Each of the arrays 904A-904D capturesphotons and outputs electronic signals. The signal processing circuit908, in certain embodiments, processes signals for each of theindividual arrays 904. The signal processing circuit 910 may combine theoutput from signal processing 908 into output data (usually in the formof a recombined full color image). Each array and the related signalprocessing circuitry may be tailored to address a specific band ofvisible spectrum.

Each of lenses 912A-912D may be tailored for the respective wavelengthof the respective array. Lenses are approximately the same size as theunderlying array 904, and will differ from one another in size and shapedepending upon the dimensions of the underlying array. In alternativeembodiments a lens could cover only a portion of an array, and couldextend beyond the array. Lenses can comprise any suitable material ormaterials, including for example, glass and plastic. Lenses can be dopedin any suitable manner, such as to impart a color filtering,polarization, or other property. Lenses can be rigid or flexible.

In the example of FIG. 9, each lens, array, and signal processingcircuit constitutes an image generating subsystem for a band of visiblespectrum (e.g., red, blue, green, etc). These individual images are thencombined with additional signal processing circuitry within thesemiconductor chip to form a full image for output.

Although the digital camera subsystem 904 is depicted in a fourarray/lens configuration, the digital camera subsystem can be employedin a configuration having any number of arrays/lenses and anycombination of shapes of arrays/lenses. FIG. 10 is a block diagram of adigital camera 1000 having a three array/lens configuration, under anembodiment. The digital camera 1000 includes a digital camera subsystem1002 that includes three lenses. The digital camera 1000 furtherincludes a circuit board 1012, a peripheral user interface electronics1010 (here represented as a shutter button, but could also includedisplay and/or one or more other output devices, setting controls and/orone or more additional input devices etc), a power supply 1006, andelectronic image storage media 1004. The digital camera 1000 may furtherinclude a housing and a shutter assembly (not shown), which controls anaperture 1014 and passage of light into the digital camera 1000.

FIG. 11 is a block diagram of a digital camera subsystem that employsseparate arrays, e.g., arrays 1104A-1104D, on one image sensor, incontrast to the prior art. For example, typical prior art approachesemploy a Bayer pattern (or variations thereof), perform operationsacross the array (a pixel at a time), and integrate each set of fourpixels (for example, red/green/blue/green or variation thereof) from thearray into a single full color pixel.

Each of the arrays 1104 focuses on a specific band of visible spectrum.Each lens only needs to pass a respective color (1106A-1106D) on to theimage sensor. The traditional color filter sheet is eliminated. Eacharray 1104 outputs signals to signal processing circuitry. Signalprocessing circuitry for each of these arrays is also tailored for eachof the bands of visible spectrum. In effect, individual images arecreated for each of these arrays. Following this process, the individualimages are combined or to form one full color or black/white image. Bytailoring each array and the associated signal processing circuitry, ahigher quality image can be generated than the image resulting fromtraditional image sensors of like pixel count.

As such, each array may be tuned to be more efficient in capturing andprocessing the image in that particular color. Individual lenses(1112A-D) can be tailored for the array's band of spectrum.

FIG. 12 is a block diagram of arrays 1204A-1204D. Each array 1204receives a respective color as passed by a respective lens. Thetraditional color filter sheet is eliminated. Each array 1204 outputssignals to signal processing circuitry. Signal processing circuitry foreach of these arrays is also tailored for each of the bands of visiblespectrum. In effect, individual images are created for each of thesearrays. Following this process, the individual images are combined or toform one full color or black/white image. By tailoring each array andthe associated signal processing circuitry, a higher quality image canbe generated than the image resulting from traditional image sensors oflike pixel count.

FIG. 13 is a block diagram of processing circuitry of a digital camerasubsystem, under an embodiment. FIG. 13 includes an array 1304,including arrays 1304A-1304D, and signal processing circuitry (alsoreferred to as image processing circuitry) 1414 and 1416. Each arrayoutputs signals to signal processing circuitry.

FIG. 14 is a block diagram of image processing circuitry 1414 and 1416.Within the image processing circuitry 1414, each array can be processedseparately to tailor the processing to the respective bands of spectrum.

Column logic 1414.1A-1414.1D is the portion of the signal processingcircuitry that reads the signals from the pixels. For example, thecolumn logic 1414.1A reads signals from the pixels in array 1404A.Column logic 1414.1B reads signals from the pixels in array 1404B.Column logic 1414.1C reads signals from the pixels in array 1404C.Column logic 1414.1D reads signals from the pixels in array 1404D.

Since an array is targeting a specific wavelength, wavelengths, band ofwavelength, or band of wavelengths, the column logic may have differentintegration times for each array enhancing dynamic range and/or colorspecificity. Signal processing circuitry complexity for each array canbe substantially reduced since logic may not have to switch betweenextreme color shifts.

Analog Signal Logic (ASL) 1414.2A-1414.2D for each array may be colorspecific. As such, the ASL processes a single color and therefore can beoptimized for gain, noise, dynamic range, linearity, etc. Due to colorsignal separation, dramatic shifts in the logic and settling time arenot required as the amplifiers and logic do not change on a pixel bypixel (color to color) basis as in traditional Bayer patterned designs.

Black level control 1414.3A-1414.3D assesses the level of noise withinthe signal, and filters it out. With each array focused upon a narrowerband of visible spectrum than traditional image sensors, the black levelcontrol can be more finely tuned to eliminate noise.

Exposure control 1414.4A-1414.4D measures the overall volume of lightbeing captured by the array and adjusts the capture time for imagequality. Traditional cameras must make this determination on a globalbasis (for all colors). The embodiments describe herein allow forexposure control to occur differently for each array and targeted bandof wavelengths.

These processed images are then passed to a second group of signalprocessing circuitry 1416. First, image processing logic 1416.1integrates the multiple color planes into a single color image. Theimage is adjusted for saturation, sharpness, intensity, hue, artifactremoval, and defective pixel correction.

In an embodiment, the final two operations include encoding the signalinto standard protocols such as MPEG, JPEG, etc. in an encoder 1416.2before passing the result to a standard output interface 1416.3, such asUSB.

Although the signal processing circuitries 1414 and 1416 are shown atspecific areas of the image sensor, the signal processing circuitries1414 and 1416 can be placed anywhere on the chip and subdivided in anyfashion. The signal processing circuitries are often placed in multiplelocations.

As previously stated, the image sensor 1404 generally includes asemiconductor chip having several higher order features includingmultiple arrays (1404A-1404D), and signal processing circuitry 1414, inwhich each array and the related signal processing circuitry ispreferably tailored to address a specific band of visible spectrum. Asnoted above, the image sensor array can be configured using any multiplenumbers and shapes of arrays.

The image sensor 1404 can be constructed using any suitable technology,including silicon and germanium technologies. The pixels can be formedin any suitable manner, can be sized and dimensioned as desired, and canbe distributed in any desired pattern. Pixels that are distributedwithout any regular pattern may also be used.

Any range of visible spectrum can be applied to each array depending onthe specific interest of the customer. Further, an infrared array couldalso be employed as one of the array/lens combinations giving low lightcapabilities to the sensor.

As previously described, arrays 1404A-1404D may be of any size or shape.While some figures referenced herein show the arrays as individual,discrete sections of the image sensor, these arrays may also betouching. There may also be one large array configured such that thearray is subdivided into sections, and each section is focused upon oneband of spectrum, creating the same effect as separate arrays on thesame chip.

Although the well depth of the photo detectors across each individualarray 1404 may be the same, the well depth of any given array may bedifferent from that of other arrays of the sensor subsystem. A photodetector includes an area or portion of the photo detector thatcaptures, collects, is responsive to, detects and/or senses theintensity illumination of incident light. In some embodiments, the welldepth is the distance from the surface of the photo detector to a dopedregion.

Selection of an appropriate well depth depends on many factors,including the targeted band of visible spectrum. Since each entire arrayis likely to be targeted at one band of visible spectrum (e.g., red) thewell depth can be configured to capture that wavelength and ignoreothers (e.g., blue, green). Doping of the semiconductor material in thecolor specific arrays can further be used to enhance the selectivity ofthe photon absorption for color-specific wavelengths.

In various embodiments, a digital camera subsystem can have multipleseparate arrays on a single image sensor, each with its own lens. Thesimple geometry of smaller, multiple arrays allows for a smaller lenses(e.g., smaller diameter, thickness and focal length), which allows forreduced stack height in the digital camera.

The lens and frame concept is applicable to traditional image sensors(without the traditional color filter sheet) to gain physical size, costand performance advantages.

Each array can advantageously be focused on one band of visible and/ordetectable spectrum. Among other things, each lens may be tuned forpassage of one specific band of wavelength. Since each lens wouldtherefore not need to pass the entire light spectrum, the number ofelements may be reduced, for example, to one or two.

Further, due to the focused bandwidth for each lens, each of the lensesmay be dyed during the manufacturing process for its respectivebandwidth (e.g., red for the array targeting the red band of visiblespectrum). Alternatively, a single color filter may be applied acrosseach lens. This process eliminates the traditional color filters (suchas the sheet of individual pixel filters) thereby reducing cost,improving signal strength and eliminating the pixel reduction barrier.

The above-described devices can include any suitable number ofcombinations, including as few as two arrays/lenses, and many more thantwo arrays/lenses. Examples include: two arrays/lenses configured asred/green and blue; two arrays/lenses configured as red and blue/green;two arrays/lenses configured as red, green, blue; four arrays/lensesconfigured as red, blue, green, emerald (for color enhancement); fourarrays/lenses configured as red, blue, green, infrared (for low lightconditions); and eight arrays/lenses configured as double the aboveconfigurations for additional pixel count and image quality.

The cameras or camera subsystems described herein are intended to beemblematic of a generic appliance containing the digital camerasubsystem. Thus, the description herein should be interpreted as beingemblematic of still and video cameras, cell phones, other personalcommunications devices, surveillance equipment, automotive applications,computers, manufacturing and inspection devices, toys, plus a wide rangeof other and continuously expanding applications. Of course thesealternative interpretations may or may not include the specificcomponents as depicted herein. For example, the circuit board may not beunique to the camera function but rather the digital camera subsystemmay be an add-on to an existing circuit board, such as in a cell phone.

Any or all of the methods and/or apparatus disclosed herein may beemployed in any type of apparatus or process including, but not limitedto still and video cameras, cell phones, other personal communicationsdevices, surveillance equipment, automotive applications, computers,manufacturing and inspection devices, toys, plus a wide range of otherand continuously expanding applications.

Although each array and the related signal processing circuitry is canbe tailored to address a specific band of visible spectrum, and eachlens may be tuned for passage of that one specific band of wavelength,there is no requirement that each such array and the related signalprocessing circuitry be tailored to address a specific band of thevisible spectrum. Nor is there any requirement that each lens be tunedfor passage of a specific band of wavelength or that each of the arraysbe located on the same semiconductor device. Indeed, the embodimentsdescribed and illustrated herein, including the specific componentsthereof, need not employ wavelength-specific features. For example, thearrays and/or signal processing circuitry need not be tailored toaddress a specific wavelength or band of wavelengths.

FIG. 15 is an exploded perspective view of a digital camera 1500, underan embodiment. The digital camera apparatus 1500 includes one or moresensor arrays, e.g., four sensor arrays 1504A-1504D, and one or moreoptics portions, e.g., four optics portions 1512A-1512D. Each of theoptics portions 1504A-1504D may include a lens, and may be associatedwith a respective one of the sensor arrays sensor arrays 1504A-1504D. Insome embodiments a support 1502, for example a frame, is provided tosupport the one or more optics portions 1512A-1512D, at least in part.Each sensor array and the respective optics portion may define anoptical channel. For example, an optical channel 1506A may be defined bythe optics portion 1512A and the sensor array 1504A. An optical channel1506B may be defined by the optics portion 1512B and the sensor array1504B. An optical channel 1506C may be defined by optics portion 1512Cand the sensor array 1504C. An optical channel 1506D may be defined byoptics portion 1512D and a sensor array 1504D. The optics portions ofthe one or more optical channels are also collectively referred to as anoptics subsystem.

The sensor arrays of the one or more optical channels are collectivelyreferred as a sensor subsystem. The two or more sensor arrays may beintegrated in or disposed on a common substrate, referred to as an imagedevice, on separate substrates, or any combination thereof. For example,where the system includes three or more sensor arrays, two or moresensor arrays may be integrated in a first substrate, and one or moreother sensor arrays may be integrated in or disposed on a secondsubstrate.

In that regard, the one or more sensor arrays 1504A-1504D, may or maynot be disposed on a common substrate. For example, in some embodimentstwo or more of the sensor arrays are disposed on a common substrate. Insome embodiments, however, one or more of the sensor arrays is notdisposed on the same substrate as one or more of the other sensorarrays. The one or more optical channels may or may not be identical toone another.

In some embodiments, one of the optical channels 1506 detects red light,one of the optical channels 1506 detects green light, and one of theoptical channels 1506 detects blue light. In some of such embodiments,one of the optical channels 1506 detects infrared light, cyan light, oremerald light. In some other embodiments, one of the optical channels1506 detects cyan light, one of the optical channels 1506 detects yellowlight, one of the optical channels 1506 detects magenta light and one ofthe optical channels 1506 detects clear light (black and white). Anyother wavelength or band of wavelengths (whether visible or invisible)combinations can also be used.

A processor 1514 is coupled to the one or more sensor arrays1504A-1504D, via one or more communication links, e.g., communicationlinks 1508A-1508D, respectively. A communication link may be any kind ofcommunication link including but not limited to, for example, wired(e.g., conductors, fiber optic cables) or wireless (e.g., acousticlinks, electromagnetic links or any combination thereof including butnot limited to microwave links, satellite links, infrared links), andcombinations thereof, each of which may be public or private, dedicatedand/or shared (e.g., a network). A communication link may include forexample circuit switching or packet switching or combinations thereof.Other examples of communication links include dedicated point-to-pointsystems, wired networks, and cellular telephone systems. A communicationlink may employ any protocol or combination of protocols including butnot limited to the Internet Protocol.

The communication link may transmit any type of information. Theinformation may have any form, including, for example, but not limitedto, analog and/or digital) e.g., a sequence of binary values, or a bitstring). The information may or may not be divided into blocks. Ifdivided into blocks, the amount of information in a block may bepredetermined or determined dynamically, and/or may be fixed (e.g.,uniform) or variable.

As will be further described hereinafter, the processor may include oneor more channel processors, each of which is coupled to a respective one(or more) of the optical channels and generates an image based at leastin part on the signal(s) received from the respective optical channel,although this is not required. In some embodiments, one or more of thechannel processors is tailored to its respective optical channel, forexample, as described herein. For example, when one of the opticalchannels is dedicated to a specific wavelength or color (or band ofwavelengths or colors) the respective channel processor may be adaptedor tailored to such wavelength or color (or band of wavelengths orcolors). Further, the gain, noise reduction, dynamic range, linearityand/or any other characteristic of the processor, or combinations ofsuch characteristics, may be adapted to improve and/or optimize theprocessor to such wavelength or color (or band of wavelengths orcolors). Tailoring the channel processing to the respective opticalchannel may facilitate generating an image of a quality that is higherthan the quality of images resulting from traditional image sensors oflike pixel count. In addition, providing each optical channel with adedicated channel processor may help to reduce or simplify the amount oflogic in the channel processors as the channel processor may not need toaccommodate extreme shifts in color or wavelength, e.g., from a color(or band of colors) or wavelength (or band of wavelengths) at oneextreme to a color (or band of colors) or wavelength (or band ofwavelengths) at another extreme.

In operation, an optics portion of a optical channel receives light fromwithin a field of view and transmits one or more portions of such light,e.g., in the form of an image at an image plane. The sensor arrayreceives one or more portions of the light transmitted by the opticsportion and provides one or more output signals indicative thereof. Theone or more output signals from the sensor array are supplied to theprocessor. In some embodiments, the processor generates one or moreoutput signals based, at least in part, on the one or more signals fromthe sensor array. In some other embodiments, the processor may generatea combined image based, at least in part, on the images from two or moreof such optical channels.

Although the processor 1514 is shown separate from the one or moresensor arrays 1504A-1504D, the processor 1514, or portions thereof, mayhave any configuration and may be disposed in one or more locations. Forexample, certain operations of the processor may be distributed to orperformed by circuitry that is integrated in or disposed on the samesubstrate or substrates as one or more of the one or more of the sensorarrays and certain operations of the processor are distributed to orperformed by circuitry that is integrated in or disposed on one or moresubstrates that are different from (whether such one or more differentsubstrates are physically located within the camera or not) thesubstrates the one or more of the sensor arrays are integrated in ordisposed on.

The digital camera apparatus 1500 may or may not include a shutter, aflash and/or a frame to hold the components together.

FIGS. 16A-16D are schematic exploded representations of one embodimentof an optics portion, such as optic portion 1512A, under an embodiment.In FIG. 16A, the optics portion 1512A includes one or more lenses, e.g.,a complex aspherical lens module 1680, one or more color coatings, e.g.,a color coating 1682, one or more masks, e.g., an auto focus mask 1684,and one or more IR coatings, e.g., an IR coating 1686.

Lenses can comprise any suitable material or materials, including forexample, glass and plastic. Lenses can be doped in any suitable manner,such as to impart a color filtering, polarization, or other property.Lenses can be rigid or flexible. In this regard, some embodiments employa lens (or lenses) having a dye coating, a dye diffused in an opticalmedium (e.g., a lens or lenses), a substantially uniform color filterand/or any other filtering technique through which light passes to theunderlying array.

The color coating 1682 helps the optics portion filter (or substantiallyattenuate) one or more wavelengths or bands of wavelengths. The autofocus mask 1684 may define one or more interference patterns that helpthe digital camera apparatus perform one or more auto focus functions.The IR coating 1686 helps the optics portion 1512A filter a wavelengthor band of wavelength in the IR portion of the spectrum.

The one or more color coatings, e.g., color coating 1682, one or moremasks, e.g., mask 1684, and one or more IR coatings, e.g., IR coating1686 may have any size, shape and/or configuration.

In some embodiments, as shown in FIG. 16B, one or more of the one ormore color coatings, e.g., the color coating 1682, are disposed at thetop of the optics portion. Some embodiments of the optics portion(and/or components thereof) may or may not include the one or more colorcoatings, one or more masks and one or more IR coatings and may or maynot include features in addition thereto or in place thereof.

In some embodiments, as shown in FIG. 16C, one or more of the one ormore color coatings, e.g., the color coating 1682, are replaced by oneor more filters 1688 disposed in the optics portion, e.g., disposedbelow the lens. In other embodiments, as shown in FIG. 16D, one or moreof the color coatings are replaced by one or more dyes diffused in thelens.

The one or more optics portions, e.g., optics portions 1512A-1512D ofFIG. 15, may or may not be identical to one another. In someembodiments, for example, the optics portions are identical to oneanother. In some other embodiments, one or more of the optics portionsare different, in one or more respects, from one or more of the otheroptics portions. For example, in some embodiments, one or more of thecharacteristics (for example, but not limited to, its type ofelement(s), size, response, and/or performance) of one or more of theoptics portions is tailored to the respective sensor array and/or tohelp achieve a desired result. For example, if a particular opticalchannel is dedicated to a particular color (or band of colors) orwavelength (or band of wavelengths) then the optics portion for thatoptical channel may be adapted to transmit only that particular color(or band of colors) or wavelength (or band of wavelengths) to the sensorarray of the particular optical channel and/or to filter out one or moreother colors or wavelengths. In some of such embodiments, the design ofan optical portion is optimized for the respective wavelength or bandsof wavelengths to which the respective optical channel is dedicated. Itshould be understood, however, that any other configurations may also beemployed. Each of the one or more optics portions may have anyconfiguration.

In some embodiments, each of the optics portions, e.g., optics portions1512A-1512D of FIG. 15, comprises a single lens element or a stack oflens elements (or lenslets), although, as stated above. For example, insome embodiments, a single lens element, multiple lens elements and/orcompound lenses, with or without one or more filters, prisms and/ormasks are employed.

An optical portion can also contain other optical features that aredesired for digital camera functionality and/or performance. Forexample, these features can include electronically tunable filters,polarizers, wavefront coding, spatial filters (masks), and otherfeatures not yet anticipated. Some of the features (in addition to thelenses) are electrically operated (such as a tunable filter), or aremechanically movable with MEMs mechanisms.

In some embodiments, one or more photochromic (or photochromatic)materials are employed in one or more of the optical portions. The oneor more materials may be incorporated into an optical lens element or asanother feature in the optical path, for example, above one or more ofthe sensor arrays. In some embodiments, photochromatic materials may beincorporated into a cover glass at the camera entrance (common aperture)to all optics (common to all optical channels), or put into the lensesof one or more optical channels, or into one or more of the otheroptical features included into the optical path of an optics portionover any sensor array.

FIGS. 17A-17C are schematic representations of one embodiment of asensor array 1704. The sensor array is similar to one of the sensorarrays 1504A-1504D of FIG. 15, foe example. As shown in FIG. 17A, thesensor array 1704 is coupled to circuits 1770, 1772, and 1774. Thesensor array sensor array 1704 captures light and converts it into oneor more signals, such as electrical signals, which are supplied to oneor more of the circuits 1770, 1772, and 1774. The sensor array 1704includes a plurality of sensor elements such as for example, a pluralityof identical photo detectors (sometimes referred to as “pictureelements” or “pixels”), e.g., pixels 1780 _(1,1)-1780 _(n,m). The photodetectors 1780 _(1,1)-1780 _(n,m), are arranged in an array, for examplea matrix-type array. The number of pixels in the array may be, forexample, in a range from hundreds of thousands to millions. The pixelsmay be arranged for example, in a two-dimensional array configuration,for example, having a plurality of rows and a plurality of columns,e.g., 640 by 480, 1280 by 1024, etc. However, the pixels can be sizedand dimensioned as desired, and can be distributed in any desiredpattern. Pixels that are distributed without any regular pattern canalso used. Referring to FIG. 17B, a pixel, for example pixel 1780_(1,1), may be viewed as having x and y dimensions, although the photoncapturing portion of a pixel may or may not occupy the entire area ofthe pixel and may or may not have a regular shape. In some embodiments,the sensor elements are disposed in a plane, referred to herein as asensor plane. The sensor may have orthogonal sensor reference axes,including for example, an x-axis, a y-axis, and a z-axis, and may beconfigured so as to have the sensor plane parallel to the x-y plane XYand directed toward the optics portion of the optical channel. Eachoptical channel has a field of view corresponding to an expanse viewableby the sensor array. Each of the sensor elements may be associated witha respective portion of the field of view.

The sensor array may employ any type of technology, for example, but notlimited to MOS pixel technologies (e.g., one or more portions of thesensor are implemented in “Metal Oxide Semiconductor” technology),charge coupled device (CCD) pixel technologies, or combination of both.The sensor array may comprise any suitable material or materials,including, but not limited to, silicon, germanium and/or combinationsthereof. The sensor elements or pixels may be formed in any suitablemanner.

In operation, the sensor array 1704A, is exposed to light on asequential line per line basis (similar to a scanner, for example) orglobally (similar to conventional film camera exposure, for example).After being exposed to light for certain period of time (exposure time),the pixels 1780 _(1,1)-1780 _(n,m), are read out, e.g., on a sequentialline per line basis.

In some embodiments, circuitry 1770, also referred to as column logic1770, is used to read the signals from the pixels 1780 _(1,1)-1780_(n,m). FIG. 17C is a schematic representation of a pixel circuit. Thepixels 1780 _(1,1)-1780 _(n), also referred to as sensor elements, maybe accessed one row at a time by asserting one of the word lines 1782,which run horizontally through the sensor array 1704A. A single pixel1780 _(1,1) is shown. Data is passed into and/or out of the pixel 1780_(1,1) via bit lines (such as bit line 1784) which run verticallythrough the sensor array 1704A.

The pixels are not limited to the configurations shown in FIGS. 17A-17C.As stated above, each of the one or more sensor arrays may have anyconfiguration (e.g., size, shape, pixel design).

The sensor arrays 1502A-1502D of FIG. 15 may or may not be identical toone another. In some embodiments, for example, the sensor arrays areidentical to one another. In some other embodiments, one or more of thesensor arrays are different, in one or more respects, from one or moreof the other sensor arrays. For example, in some embodiments, one ormore of the characteristics (for example, but not limited to, its typeof element(s), size (for example, surface area), and/or performance) ofone or more of the sensor arrays is tailored to the respective opticsportion and/or to help achieve a desired result.

FIG. 18 is a schematic cross-sectional view of a digital cameraapparatus 1800 including a printed circuit board 1820 of a digitalcamera on which the digital camera elements are mounted, under anembodiment. In this embodiment, the one or more optics portions, e.g.,optics portions 1812A and 1812B are seated in and/or affixed to asupport 1814. The support 1814 (for example a frame) is disposedsuperjacent a first bond layer 1822, which is disposed superjacent animage device 1820, in or on which sensor portions 1812A-1812D (sensorportions 1812C and 1812D are not shown), are disposed and/or integrated.The image device 1820 is disposed superjacent a second bond layer 1824which is disposed superjacent the printed circuit board 1821.

The printed circuit board 1821 includes a major outer surface 1830 thatdefines a mounting region on which the image device 1820 is mounted. Themajor outer surface 1830 may further define and one or more additionalmounting regions (not shown) on which one or more additional devicesused in the digital camera may be mounted. One or more pads 1832 areprovided on the major outer surface 1830 of the printed circuit board toconnect to one or more of the devices mounted thereon.

The image device 1820 includes the one or more sensor arrays (notshown), and one or more electrically conductive layers. In someembodiments, the image device 1820 further includes one, some or allportions of a processor for the digital camera apparatus 1800. The imagedevice 1820 further includes a major outer surface 1840 that defines amounting region on which the support 1814 is mounted.

The one or more electrically conductive layers may be patterned todefine one or more pads 1842 and one or more traces (not shown) thatconnect the one or more pads to one or more of the one or more sensorarrays. The pads 1842 are disposed, for example, in the vicinity of theperimeter of the image device 1820, for example along one, two, three orfour sides of the image device 1820. The one or more conductive layersmay comprise, for example, copper, copper foil, and/or any othersuitably conductive material(s).

A plurality of electrical conductors 1850 may connect one or more of thepads 1842 on the image device 1820 to one or more of the pads 1832 onthe circuit board 1821. The conductors 1850 may be used, for example, toconnect one or more circuits on the image device 1820 to one or morecircuits on the printed circuit board 1821.

The first and second bond layers 1822 and 1824 may comprise any suitablematerial(s), including but not limited to adhesive, and may comprise anysuitable configuration. The first and second bond layers 1822, 1824 maycomprise the same material(s) although this is not required. As usedherein, a bond layer may be continuous or discontinuous. For example, aconductive layer may be an etched printed circuit layer. Moreover, abond layer may or may not be planar or even substantially planar. Forexample, a conformal bond layer on a non-planar surface will benon-planar.

FIG. 19 is a schematic perspective view of a digital camera apparatushaving one or more optics portions with the capability to provide colorseparation in accordance with one embodiment of the present invention.In some of such embodiments, one or more of the optics portions, e.g.,optics portion 1912C includes an array of color filters, for example,but not limited to a Bayer patter. In some of such embodiments, one ormore of the optics portions, e.g., optics portion 1912C has thecapability to provide color separation similar to that which is providedby a color filter array.

In some embodiments, the lens and/or filter of the optical channel maytransmit both of such colors or bands of colors, and the optical channelmay include one or more mechanisms elsewhere in the optical channel toseparate the two colors or two bands of colors. For example, a colorfilter array may be disposed between the lens and the sensor array,and/or the optical channel may employ a sensor capable of separating thecolors or bands of colors. In some of the latter embodiments, the sensorarray may be provided with pixels that have multiband capability, e.g.,two or three colors. For example, each pixel may comprise two or threephotodiodes, wherein a first photodiode is adapted to detect a firstcolor or first band of colors, a second photodiode is adapted to detecta second color or band of colors and a third photodiode is adapted todetect a third color or band of colors. One way to accomplish this is toprovide the photodiodes with different structures and/or characteristicsthat make them selective, such that the first photodiode has a highersensitivity to the first color or first band of colors than to thesecond color or band of colors, and the second photodiode has a highersensitivity to the second color or second band of colors than to thefirst color or first band of colors. Alternatively, the photodiodes aredisposed at different depths in the pixel, taking advantage of thedifferent penetration and absorption characteristics of the differentcolors or bands of colors. For example, blue and blue bands of colorspenetrate less (and are thus absorbed at a lesser depth) than green andgreen bands of colors, which in turn penetrate less (and are thusabsorbed at a lesser depth) than red and red bands of colors. In someembodiments, such a sensor array is employed, even though the pixels maysee only one particular color or band of colors, for example, to inorder to adapt such sensor array to the particular color or band ofcolors.

FIG. 20A is a block diagram of a processor 2002 of a digital camerasubsystem 2000, under an embodiment. In this embodiment, the processor2002 includes one or more channel processors, one or more imagepipelines, and/or one or more image post processors. Each of the channelprocessors is coupled to a respective one of the optical channels (notshown) and generates an image based at least in part on the signal(s)received from the respective optical channel. In some embodiments theprocessor 2002 generates a combined imaged based at least in part on theimages from two or more of the optical channels. In some embodiments,one or more of the channel processors are tailored to its respectiveoptical channel, as previously described.

In various embodiments, the gain, noise reduction, dynamic range,linearity and/or any other characteristic of the processor, orcombinations of such characteristics, may be adapted to improve and/oroptimize the processor to a wavelength or color (or band of wavelengthsor colors). Tailoring the channel processing to the respective opticalchannel makes it possible to generate an image of a quality that ishigher than the quality of images resulting from traditional imagesensors of like pixel count. In such embodiments, providing each opticalchannel with a dedicated channel processor helps to reduce or simplifythe amount of logic in the channel processors, as the channel processormay not need to accommodate extreme shifts in color or wavelength, e.g.,from a color (or band of colors) or wavelength (or band of wavelengths)at one extreme to a color (or band of colors) or wavelength (or band ofwavelengths) at another extreme

The images (and/or data which is representative thereof) generated bythe channel processors are supplied to the image pipeline, which maycombine the images to form a full color or black/white image. The outputof the image pipeline is supplied to the post processor, which generatesoutput data in accordance with one or more output formats.

FIG. 20B shows one embodiment of a channel processor. In thisembodiment, the channel processor includes column logic, analog signallogic, and black level control and exposure control. The column logic iscoupled to the sensor and reads the signals from the pixels. Each of thecolumn logic, analog signal logic, black level control and exposurecontrol can be configured for processing as appropriate to thecorresponding optical channel configuration (e.g., specific wavelengthor color, etc.). For example, the analog signal logic is optimized, ifdesired, for processing. Therefore, gain, noise, dynamic range and/orlinearity, etc., are optimized as appropriate to the correspondingoptical channel configuration (e.g., a specific wavelength or color,etc.). As another example, the column logic may employ an integrationtime or integration times adapted to provide a particular dynamic rangeas appropriate to the corresponding optical channel.

The output of the analog signal logic is supplied to the black levelcontrol, which determines the level of noise within the signal, andfilters out some or all of such noise. If the sensor coupled to thechannel processor is focused upon a narrower band of visible spectrumthan traditional image sensors, the black level control can be morefinely tuned to eliminate noise.

The output of the black level control is supplied to the exposurecontrol, which measures the overall volume of light being captured bythe array and adjusts the capture time for image quality. Traditionalcameras must make this determination on a global basis (for all colors).In the camera of an embodiment, however, the exposure control can bespecifically adapted to the wavelength (or band of wavelengths) to whichthe sensor is configured. Each channel processor is thus able to providea capture time that is specifically adapted to the sensor and/orspecific color (or band of colors) targeted, and which may be differentthan the capture time provided by another channel processor for anotheroptical channel.

FIG. 20C is a block diagram of the image pipeline, under an embodiment.In this embodiment, the image pipeline includes two portions. The firstportion includes a color plane integrator and an image adjustor. Thecolor plane integrator receives an output from each of the channelprocessors and integrates the multiple color planes into a single colorimage. The output of the color plane integrator, which is indicative ofthe single color image, is supplied to the image adjustor, which adjuststhe single color image for saturation, sharpness, intensity and hue. Theadjustor also adjusts the image to remove artifacts and any undesiredeffects related to bad pixels in the one or more color channels. Theoutput of the image adjustor is supplied to the second portion of thepipeline, which provides auto focus, zoom, windowing, pixel binning andcamera functions.

FIG. 20D is a block diagram of the image post processor, under anembodiment. In this embodiment, the image post processor includes anencoder and an output interface. The encoder receives the output signalfrom the image pipeline and provides encoding to supply an output signalin accordance with one or more standard protocols (e.g., MPEG and/orJPEG). The output of the encoder is supplied to the output interface,which provides encoding to supply an output signal in accordance with astandard output interface, e.g., universal serial bus (USB) interface.

FIG. 21 is a block diagram of digital camera system, including systemcontrol components, under an embodiment. The system control portionincludes a serial interface, configuration registers, power management,voltage regulation and control, timing and control, a camera controlinterface and a serial interface, but is not so limited. In someembodiments, the camera interface comprises an interface that processessignals that are in the form of high level language (HLL) instructions.In some embodiments the camera interface comprises an interface thatprocesses control signals that are in the form of low level language(LLL) instructions and/or of any other form now known or laterdeveloped. Some embodiments may process both HLL instructions and LLLinstructions.

As used herein, the following terms are interpreted as described below,unless the context requires a different interpretation.

“Array” means a group of photodetectors, also know as pixels, whichoperate in concert to create one image. The array captures photons andconverts the data to an electronic signal. The array outputs this rawdata to signal processing circuitry that generates the image sensorimage output.

“Digital Camera” means a single assembly that receives photons, convertsthem to electrical signals on a semiconductor device (“image sensor”),and processes those signals into an output that yields a photographicimage. The digital camera would included any necessary lenses, imagesensor, shutter, flash, signal processing circuitry, memory device, userinterface features, power supply and any mechanical structure (e.g.circuit board, housing, etc) to house these components. A digital cameramay be a stand-alone product or may be imbedded in other appliances,such as cell phones, computers or the myriad of other imaging platformsnow available or to be created in the future, such as those that becomefeasible as a result of this invention.

“Digital Camera Subsystem” (DCS) means a single assembly that receivesphotons, converts them to electrical signals on a semiconductor device(“image sensor”) and processes those signals into an output that yieldsa photographic image. The Digital Camera Subsystem includes anynecessary lenses, image sensor, signal processing circuitry, shutter,flash and any frame to hold the components as may be required. The powersupply, memory devices and any mechanical structure are not necessarilyincluded.

“Electronic media” means that images are captured, processed and storedelectronically as opposed to the use of film.

“Frame” or “thin plate” means the component of the DCS that is used tohold the lenses and mount to the image sensor.

“Image sensor” means the semiconductor device that includes the photondetectors (“pixels”), processing circuitry and output channels. Theinputs are the photons and the output is the image data.

“Lens” means a single lens or series of stacked lenses (a column oneabove the other) that shape light rays above an individual array. Whenmultiple stacks of lenses are employed over different arrays, they arecalled “lenses.”

“Package” means a case or frame that an image sensor (or anysemiconductor chip) is mounted in or on, which protects the imager andprovides a hermetic seal.

“Packageless” refers to those semiconductor chips that can be mounteddirectly to a circuit board without need of a package.

The terms “Photo-detector” and “pixels” mean an electronic device thatsenses and captures photons and converts them to electronic signals.These extremely small devices are used in large quantities (hundreds ofthousands to millions) in a matrix to capture an image.

“Semiconductor Chip” means a discrete electronic device fabricated on asilicon or similar substrate, which is commonly used in virtually allelectronic equipment.

“Signal Processing Circuitry” means the hardware and software within theimage sensor that translates the photon input information intoelectronic signals and ultimately into an image output signal.

Aspects of the digital camera systems and methods described herein maybe implemented as functionality programmed into any of a variety ofcircuitry, including programmable logic devices (PLDs), such as fieldprogrammable gate arrays (FPGAs), programmable array logic (PAL)devices, electrically programmable logic and memory devices and standardcell-based devices, as well as application specific integrated circuits(ASICs). Some other possibilities for implementing aspects of thedigital camera systems and methods include: microcontrollers with memory(such as electronically erasable programmable read only memory(EEPROM)), embedded microprocessors, firmware, software, etc.Furthermore, aspects of the digital camera systems and methods may beembodied in microprocessors having software-based circuit emulation,discrete logic (sequential and combinatorial), custom devices, fuzzy(neural) logic, quantum devices, and hybrids of any of the above devicetypes. Of course the underlying device technologies may be provided in avariety of component types, e.g., metal-oxide semiconductor field-effecttransistor (MOSFET) technologies like complementary metal-oxidesemiconductor (CMOS), bipolar technologies like emitter-coupled logic(ECL), polymer technologies (e.g., silicon-conjugated polymer andmetal-conjugated polymer-metal structures), mixed analog and digital,etc.

It should be noted that components of the various systems and methodsdisclosed herein may be described using computer aided design tools andexpressed (or represented), as data and/or instructions embodied invarious computer-readable media, in terms of their behavioral, registertransfer, logic component, transistor, layout geometries, and/or othercharacteristics. Computer-readable media in which such formatted dataand/or instructions may be embodied include, but are not limited to,non-volatile storage media in various forms (e.g., optical, magnetic orsemiconductor storage media).

Examples of transfers of such formatted data and/or instructions bycarrier waves include, but are not limited to, transfers (uploads,downloads, e-mail, etc.) over the Internet and/or other computernetworks via one or more data transfer protocols (e.g., HTTP, FTP, SMTP,etc.). When received within a computer system via one or morecomputer-readable media, such data and/or instruction-based expressionsof the above described systems and methods may be processed by aprocessing entity (e.g., one or more processors) within the computersystem in conjunction with execution of one or more other computerprograms.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense as opposed to anexclusive or exhaustive sense; that is to say, in a sense of “including,but not limited to.” Words using the singular or plural number alsoinclude the plural or singular number respectively. Additionally, thewords “herein,” “hereunder,” “above,” “below,” and words of similarimport refer to this application as a whole and not to any particularportions of this application. When the word “or” is used in reference toa list of two or more items, that word covers all of the followinginterpretations of the word: any of the items in the list, all of theitems in the list and any combination of the items in the list.

The above description of illustrated embodiments of the digital camerasystems and methods is not intended to be exhaustive or to limit thedigital camera systems and methods to the precise form disclosed. Whilespecific embodiments of, and examples for, the digital camera systemsand methods are described herein for illustrative purposes, variousequivalent modifications are possible within the scope of the digitalcamera systems and methods, as those skilled in the relevant art willrecognize. The teachings of the digital camera systems and methodsprovided herein can be applied to other processing systems and methods,not only for the systems and methods described above.

The elements and acts of the various embodiments described above can becombined to provide further embodiments. These and other changes can bemade to the digital camera systems and methods in light of the abovedetailed description.

In general, in the following claims, the terms used should not beconstrued to limit the digital camera systems and methods to thespecific embodiments disclosed in the specification and the claims, butshould be construed to include all systems that operate under theclaims. Accordingly, the digital camera systems and methods are notlimited by the disclosure, but instead the scope of the digital camerasystems and methods is to be determined entirely by the claims.

While certain aspects of the digital camera systems and methods arepresented below in certain claim forms, the inventors contemplate thevarious aspects of the digital camera systems and methods in any numberof claim forms. Accordingly, the inventors reserve the right to addadditional claims after filing the application to pursue such additionalclaim forms for other aspects of the digital camera systems and methods.

1. A digital camera comprising: a first channel and a second channel,wherein the first channel includes a first optics component and a firstsensor, wherein the second channel includes a second optics componentand a second sensor, and wherein the first sensor includes a first arrayof photo-detectors and the second sensor includes a second array ofphoto-detectors; and a processing component operatively coupled to thefirst channel and to the second channel, wherein the processingcomponent is configured to separately control an integration time ofeach channel, wherein a first integration time of the first channel isless than a second integration time of the second channel, and whereinthe processing component is configured to combine data captured by eachof the first channel and the second channel to generate an image.
 2. Thedigital camera of claim 1, further comprising an interface operativelycoupled to the processing component, wherein the interface is configuredto receive the first integration time as an input to the digital camera.3. The digital camera of claim 1, further comprising an interfaceoperatively coupled to the processing component, wherein the interfaceis configured to receive an indication of an amount of incident light asan input.
 4. The digital camera of claim 3, wherein processing componentis further configured to determine at least the first integration timebased at least in part on the indication of the amount of incidentlight.
 5. The digital camera of claim 1, wherein the first integrationtime is used to control an amount of electrical charge placed on one ormore storage devices associated with the first sensor of the firstchannel.
 6. The digital camera of claim 5, wherein the one or morestorage devices comprise one or more capacitors, and wherein eachphoto-detector in the first array of photo-detectors includes acapacitor.
 7. The digital camera of claim 1, further comprising asemiconductor substrate on which the first channel and the secondchannel are integrated.
 8. The digital camera of claim 1, wherein thefirst integration time falls with a range of integration times, andwherein the range of integration times has a minimum integration timeand a maximum integration time.
 9. The digital camera of claim 8,wherein a ratio of the maximum integration time to the minimumintegration time is
 25. 10. The digital camera of claim 8, furthercomprising a third channel operatively coupled to the processingcomponent, wherein the first channel, the second channel, and the thirdchannel each have a distinct integration time within the range ofintegration times so that one or more bright objects and one or moredark objects are captured in the image.
 11. The digital camera of claim1, wherein the first sensor and the second sensor are configured toimage a same field of view.
 12. The digital camera of claim 1, whereinthe image corresponds to a first frame, and wherein the processingcomponent is further configured to determine one or more integrationtimes for a second frame based at least in part on the image.
 13. Atangible computer-readable medium having stored thereon,computer-executable instructions that, upon execution, cause a digitalcamera to perform a method comprising: identifying an integration timefor each of a plurality of channels of the digital camera, wherein eachof the plurality of channels includes a sensor; controlling each sensorbased at least in part on the integration time corresponding to achannel that includes the sensor, wherein a first integration time of afirst channel is less than a second integration time of a secondchannel; and generating an image by combining data captured with eachsensor.
 14. The tangible computer-readable medium of claim 13, whereinidentifying the integration time for each of the plurality of channelscomprises receiving an input through an interface of the digital camera.15. The tangible computer-readable medium of claim 14, wherein the inputspecifies at least one integration time.
 16. The tangiblecomputer-readable medium of claim 14, wherein the input comprises anindication of an amount of light incident on a subject of the image. 17.The tangible computer-readable medium of claim 13, wherein controllingeach sensor comprises providing an electrical charge to each sensor fora period of time, wherein the period of time comprises the integrationtime corresponding to the sensor.
 18. The tangible computer-readablemedium of claim 17, wherein the electrical charge is stored on or morecapacitors of the sensor.
 19. The tangible computer-readable medium ofclaim 13, further comprising determining a subsequent integration timefor each channel to use during a subsequent frame, wherein eachsubsequent integration time is determined based at least in part on theimage.
 20. The tangible computer-readable medium of claim 13, whereinidentifying the integration time for each of the plurality of channelsincludes accessing predetermined integration times from a memory.
 21. Amethod comprising: identifying an integration time for each of aplurality of sensors of a digital camera, wherein each of the pluralityof sensors comprises a plurality of photo-detectors; controlling eachsensor based at least in part on the integration time corresponding tothe sensor, wherein a first integration time of a first sensor is lessthan a second integration time of a second sensor; capturing data witheach of the plurality of sensors, wherein the data captured by eachsensor is based at least in part on the integration time of the sensor;and generating an image by combining the data captured by each of theplurality of sensors.
 22. The method of claim 21, wherein identifyingthe integration time for each of the plurality of sensors comprisesreceiving an input through an interface of the digital camera, whereinthe input includes at least one of a specific integration time or anamount of light incident on a subject of the image.
 23. The method ofclaim 21, wherein controlling each sensor comprises providing anelectrical charge to each sensor for a period of time, wherein theperiod of time comprises the integration time corresponding to thesensor.
 24. The method of claim 23, wherein at least a portion of theelectrical charge is provided to each of the plurality ofphoto-detectors of the sensor.
 25. The method of claim 24, furthercomprising storing at least the portion of the electrical charge on acapacitor associated with each of the plurality of photo-detectors ofthe sensor.
 26. The method of claim 21, further comprising determining asubsequent integration time for each of the plurality of sensors basedat least in part on the image.
 27. The method of claim 21, furthercomprising analyzing a previous image generated by the digital camera,wherein the identifying of the integration time for each of theplurality of sensors is based at least in part on the analysis.
 28. Adigital camera comprising: means for identifying an integration time foreach of a plurality of channels of the digital camera, wherein each ofthe plurality of channels includes a sensor; means for controlling eachsensor based at least in part on the integration time corresponding to achannel that includes the sensor, wherein a first integration time of afirst channel is less than a second integration time of a secondchannel; and means for generating an image by combining data capturedwith each sensor.
 29. The digital camera of claim 28, further comprisingmeans for capturing the data with each sensor based at least in part onthe integration time corresponding to the channel that includes thesensor.
 30. The digital camera of claim 28, further comprising means forstoring an electrical charge at each sensor, wherein an amount of theelectrical charge is based at least in part on the integration timecorresponding to the channel that includes the sensor.
 31. The digitalcamera of claim 28, further comprising means for receiving an input,wherein the input is used by the means for identifying to identify theintegration time for each of the plurality of channels.